We present an apparatus that allows for the simultaneous measurement of mass change, heat evolution, and stress of thin film samples deposited on quartz crystal microbalances (QCMs). We show device operation at 24.85 ± 0.05 °C under 9.31 ± 0.02 bars of H2 as a reactive gas. Using a 335 nm palladium film, we demonstrate that our apparatus quantifies curvature changes of 0.001 m−1. Using the QCM curvature to account for stress induced frequency changes, we demonstrate the measurement of mass changes of 13 ng/cm2 in material systems exhibiting large stress fluctuations. We use a one-state nonlinear lumped element model to describe our system with thermal potentials measured at discrete positions by three resistance temperature devices lithographically printed on the QCM. By inputting known heat amounts through lithographically defined Cr/Al wires, we demonstrate a 150 μW calorimetric accuracy and 20 μW minimum detectable power. The capabilities of this instrument will allow for a more complete characterization of reactions occurring in nanoscale systems, such as the effects of hydrogenation in various metal films and nanostructures, as well as allow for direct stress compensation in QCM measurements.
Apparatus for combined nanoscale gravimetric, stress, and thermal measurements
Joseph B. Murray, Kevin J. Palm, Tarun C. Narayan, David K. Fork, Seid Sadat, Jeremy N. Munday; Apparatus for combined nanoscale gravimetric, stress, and thermal measurements. Rev. Sci. Instrum. 1 August 2018; 89 (8): 085106. https://doi.org/10.1063/1.5040503
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